Waffle Iron Hash Browns

one-20 ounce bag (about 3 cups) refrigerated shredded potatoes (I recommend refrigerated; using frozen or shredding your own is possible but you must thoroughly wring out in paper towels)

to 2 teaspoons dried onion flakes, or to taste

kosher salt, or to taste

freshly ground black pepper, or to taste

unsalted butter, melted

sour cream, optional for serving

freshly minced chives, optional for serving